1. Field of the Invention
The present invention relates to a confocal microscope and to a multiphoton excitation microscope.
This application is based on Japanese Patent Application No. 2006-145075, the content of which is incorporated herein by reference.
2. Description of Related Art
A confocal microscope according to the related art is disclosed, for example, in Japanese Unexamined Patent Application, Publication No. HEI-8-271792 and US Patent Application No. 2004/0113059.
Japanese Unexamined Patent Application, Publication No. HEI-8-271792 discloses a confocal microscope in which laser light is two-dimensionally scanned with two galvanometer mirrors, and fluorescence returning via the galvanometer mirrors is detected with a light detector such as a photomultiplier tube.
US Patent Application No. 2004/0113059 discloses a confocal microscope in which a digital mirror array device and a one-axis galvanometer mirror are provided in a common light path of illumination light and detection light, and a beam having a straight-line shape in cross-section is imaged on the digital mirror array device. Laser light is two-dimensionally scanned on the surface of a specimen based on the on/off operation of the digital mirror array device and the rocking motion of the galvanometer mirrors, and fluorescence returning via the digital mirror array device and the galvanometer mirror is detected by a one-dimensional line sensor.
However, when the laser light is two-dimensionally scanned with the galvanometer mirror, because the driving speed of the galvanometer mirror is delayed, a comparatively long time is required for acquiring one single image, which is not compatible with observing a fast response of the specimen.
Also, when the fluorescence is emitted from the specimen surface and returns via the galvanometer mirror, the focal position of the fluorescence focused on the light detector or the line sensor does not move, and therefore, when constructing an image, it is necessary to synchronize the light detector or the line sensor with the scanning position of the galvanometer mirror and/or the digital mirror array device. Therefore, it is necessary to perform complicated control of the light detector or the line sensor, and it is thus not possible to directly use, for example, a commercially available two-dimensional CCD camera.